Maybe those fire-breathing scaly things that like to hoard gold in caves don’t exist, or at least Smaug doesn’t — but there is more than one type of dragon.

The monstrous icthyosaur which emerged from the Rutland Water Reserve in the U.K. is now known as the Rutland Sea Dragon for obvious reasons. The 180-million-year-old skeleton is around 30 feet long, and its skull alone weighs a literal ton. This specimen is thought to be a Temnodontosaurus trigonodon, and if it is, that would also make it the hugest and most complete example of the species ever found in the U.K. It just didn’t breathe fire.

This dragon was stumbled upon by accident as Joe Davis, leader of the Rutland Water Conservation Team, eyed something unusual that appeared to be skeletal remains. It turned out to be the creature’s fossilized spine. Researcher Mark Evans of the British Antarctic Survey, and also an honorary visiting fellow at the University of Leicester, is co-leading the scientific investigation of these rare remains with fellow researcher Dean Lomax. The features appear closer to those of T. trigonodon than other enormous U.K. ichthyosaurs around the same age.

“The bigger a fossil is, the harder it is for it to have been buried before the body started to decay or became scavenged, and so the harder it is for the whole skeleton to become preserved,” Evans told SYFY WIRE. “Sometimes only an isolated skull is found, and many ichthyosaurs are missing the end of their jaws.”

Behemoths like this hardly ever show themselves (not because they’re hiding in the Lonely Mountain). For fossilization to happen, remains need to be buried in sediment as quickly as possible, which is one of the reasons some prehistoric life-forms (like a lifelike dinosaur embryo that looks as if it just fell asleep) have been found so incredibly preserved.

The more a carcass decays, the lesser the chance that the entire skeleton will end up fossilizing. Larger fossils with more bones also take more time to cover with sediment. That means there is more of a risk of decomposition and loss of part of the skeleton before it can be frozen in time.

Fossilization conditions turned out in favor of this ichthyosaur. Most other ichthyosaur specimens, have been found fragmented. Sometimes a dead ichthyosaur would float to the surface and bloat as it decomposed, with parts of it dropping off in random places at the bottom of the ocean until what was left also sank. Monster fossils are often missing their heads or have major gaps in what is recovered of their skeletons. The Rutland Sea Dragon defied expectations because just about nothing was missing, so its body must have not hung around near the surface for long. Now what Evans and his team need is proof of what species it is.

“If we are right and the Rutland Sea Dragon is a T. trigonodon, then it means that this species was not just present in the seas of the Germanic basin, but also in the British seas during the early Jurassic Period,” he said. “If it is a different species, then the giant ichthyosaurs of Britain were more diverse than we thought.”

T. trigonodon is not a new species. It terrorized the seas of what is now Germany, but if that is the species of this fossil, it might be the first one to ever appear in the U.K. Most U.K. ichthyosaur remains have been found further north, in the Cleveland Basin in Yorkshire. The largest species found there is T. crassimanus. What is now Rutland was the East Midlands Shelf, which reached all the way to mainland Europe during the early Jurassic. If the Rutland Sea Dragon is another species, it might have survived because different ichthyosaurs hunted different prey.

Some fossils with this level of preservation still have fossilized stomach or gut contents, something that Eans is hoping to find. It could give away they type of prey craved by this ichthyosaur. That might also hint at the species. The fact that icthyosaurs gave birth to live young could mean something else.

“They never came onto land and lived at sea all their lives,” Evans said. “That means it is possible that we might find fossil embryos inside the body, which would be fantastic and a first for this kind of ichthyosaur.”

So dragon-things that sound like fantasy beasts really did exist, sans the massive hoard of gold.